SIMS and Numerical Analysis of Asymmetrical Out-Diffusion of Hydrogen and Carbon in CdxZn1−xO:Eu Multilayer

This study employs secondary ion mass spectrometry (SIMS) to investigate the diffusion behavior of hydrogen and carbon in a CdxZn1−xO:Eu multilayer at different annealing temperatures (500–900 °C). The SIMS results reveal a significant out-diffusion of these elements toward the surface and diffusion to the interface region. The diffusion flow rates are asymmetric and favor the interface direction. The depth profiles of diffused elements are fitted using the forward timecentered space (FTCS) iteration method. The activation energies are determined to be 0.35 ± 0.06 eV for hydrogen and 0.33 ± 0.09 eV for carbon, suggesting an interstitial mechanism in CdxZn1−xO. The results indicate that increasing the annealing temperatures leads to a significant decrease in impurity concentrations.